Genetic and phenotypic heterogeneity in tropical calcific pancreatitis

Glycemic variability in chronic calcific pancreatitis with diabetes mellitus and its possible determinants

AIMS

To study glycemic patterns and variability in patients with pancreatic diabetes or type 3c Diabetes mellitus (DM) due to chronic pancreatitis and its subtypes and assess the role of pancreatic enzyme replacement therapy (ERT) in modulating glycemic variability.

METHODS

Patients having type 3c DM due to chronic pancreatitis, and on insulin underwent Flash continuous-glucose-monitoring (CGM) for 14 days. Parameters were compared between patients with fibrocalculous pancreatic diabetes (FCPD) and non-FCPD-chronic calcific pancreatitis (non-FCPD) and between the recipients and non-recipients of pancreatic enzyme-replacement-therapy (ERT).

RESULTS

Out of 54 patients with pancreatic diabetes, 35 patients had chronic calcific pancreatitis. They underwent CGM, median HbA1c 9.20 % (77 mmol/mol) and mean Time-In-Range (TIR) being 41.21 % (23.48). Only 5 (15.2 %) patients achieved target TIR>70 % while 16 (48.5 %) patients had high glycemic-variability [Coefficient-of-variation (CV) > 36 %]. Patients with FCPD (n = 14) had higher hypoglycemia-indices like Time-Below-Range (18.92 % vs 8.20 %; p = 0.03) and Low-Blood-Glucose-Index (18.14 % vs 6.04 %; p = 0.02) compared to non-FCPD (n = 21). HbA1c% and hyperglycemic excursions were similar in both groups. Recipients of ERT (n = 20) had lower glycemic-variability [Standard Deviation (SD) 52.15 % vs 68.14 % and CV 32.59 % vs 41.79 %, p < 0.05 for both) than non-recipients. ERT-recipients had no serious hypoglycemia within the 14 days. On subgroup analysis, lower glycemic-variability and hypoglycemia with ERT were seen only in FCPD but not in non-FCPD subgroup (50.13 vs 77.91, 30.09 vs 48.36 for SD and CV respectively, p < 0.05).

CONCLUSION

Patients with type 3c DM due to chronic pancreatitis have high frequency of hyperglycemic and hypoglycemic excursions, with those with FCPD having a particularly higher risk of hypoglycemia and glycemic-variability. Those receiving pancreatic ERT had lesser glycemic variability and hypoglycemia. The small sample size and lack of objective markers of documentation of exocrine pancreatic insufficiency like fecal elastase highlight the need for further larger studies in this field.

Lateral Pancreaticojejunostomy in a Rare Case of Chronic Calcific Pancreatitis With Peripancreatic Pseudocyst in an 18-Year-Old Male: A Case Report

Another name for the Puestow surgery is a lateral pancreaticojejunostomy. The primary pancreatic duct, which runs from the head to the tail of the organ, is opened, exposing the pancreas. In order to allow the pancreas to empty straight into the intestines, the opening of the pancreatic duct is subsequently joined to a tiny intestinal loop. For more than 50 years, this process has been used to effectively relieve pain caused by chronic pancreatitis. This technique has a very low mortality rate and a low rate of surgical complications, and a high success rate. The gradual fibrosis of the pancreas resulting in the loss of exocrine and endocrine function is known as chronic pancreatitis. Intense pain is the disease's most typical symptom. It is unclear what causes the discomfort in chronic pancreatitis. Nonetheless, a large number of these patients have dilated ducts that are made up of intervening structures and saccular dilations, a condition known as the "chain of lakes" phenomenon. Radiological investigations can be used for diagnosis in these patients. Lateral pancreaticojejunostomy is the most effective treatment option for these individuals. Preservation of endocrine and exocrine pancreatic function is another benefit of lateral pancreaticojejunostomy. With lateral pancreaticojejunostomy, chronic fibrocalcific pancreatitis that manifests as pancreatic ductal dilatation and persistent discomfort can be effectively treated. Excellent early outcomes have been observed in terms of pain alleviation as well as post-operative morbidity and mortality; however, the patient's overall outcome and long-term follow-up have not been as well defined.

Exploring the role of TLK2 mutation in tropical calcific pancreatitis: an in silico and molecular dynamics simulation study

Tropical calcific pancreatitis (TCP) is a juvenile form of non-alcoholic chronic pancreatitis seen exclusively in tropical countries. The disease poses a high risk of complications, including pancreatic diabetes and cancer, leading to significant mortality due to poor diagnosis and ineffective treatments. This study employed whole exome sequencing (WES) of 5 TCP patient samples to identify genetic variants associated with TCP. Advanced computational techniques were used to gain atomic-level insights into disease progression, including microsecond-scale long MD simulations and essential dynamics. In silico virtual screening was performed to identify potential therapeutic compounds targeting the mutant protein using the Asinex and DrugBank compound library. WES analysis predicted several single nucleotide variants (SNVs) associated with TCP, including a novel missense variant (c.T1802A or p.V601E) in the TLK2 gene. Computational analysis revealed that the p.V601E mutation significantly affected the structure of the TLK2 kinase domain and its conformational dynamics, altering the interaction profile between ATP and the binding pocket. These changes could impact TLK2's kinase activity and functions, potentially correlating with TCP progression. Promising lead compounds that selectively bind to the TLK2 mutant protein were identified, offering potential for therapeutic interventions in TCP. These findings hold great potential for future research.Communicated by Ramaswamy H. Sarma.

Early Diagnosis and Surgical Management of Tropical Chronic Pancreatitis in a Tertiary Care Rural Hospital: A Case Report

Tropical chronic pancreatitis represents a variant of chronic calcific non-alcoholic pancreatitis, typically found in adolescents and young adults, predominantly in developing nations. This condition usually presents as a classic triad of recurrent and severe abdominal pain, diabetes, and steatorrhea. As the disease progresses and diabetes develops, it is called fibrocalculous pancreatic diabetes. A defining characteristic of this ailment is the presence of pancreatic calculi, leading to duct dilation. Key features of this condition include an early onset in youth, intraductal calculi, an aggressive disease course, and a heightened susceptibility to pancreatic cancer. Diagnostic tools such as ultrasound, CT, magnetic resonance cholangiopancreatography, and endoscopic retrograde cholangiopancreatography aid in identifying the disease. Timely diagnosis and treatment significantly reduce mortality and morbidity. Our patient, a young female, presented solely with recurrent episodes of abdominal pain resembling pancreatitis, along with a normal biological profile and an absence of readily apparent symptoms. She received a diagnosis of tropical chronic pancreatitis and underwent the Partington-Rochelle procedure for surgical decompression of the main pancreatic duct.

The PRSS3P2 and TRY7 deletion copy number variant modifies risk for chronic pancreatitis

BACKGROUND

PRSS1 and PRSS2 constitute the only functional copies of a tandemly-arranged five-trypsinogen-gene cluster (i.e., PRSS1, PRSS3P1, PRSS3P2, TRY7 and PRSS2) on chromosome 7q35. Variants in PRSS1 and PRSS2, including missense and copy number variants (CNVs), have been reported to predispose to or protect against chronic pancreatitis (CP). We wondered whether a common trypsinogen pseudogene deletion CNV (that removes two of the three trypsinogen pseudogenes, PRSS3P2 and TRY7) might be associated with CP causation/predisposition.

METHODS

We analyzed the common PRSS3P2 and TRY7 deletion CNV in a total of 1536 CP patients and 3506 controls from France, Germany, India and Japan by means of quantitative fluorescent multiplex polymerase chain reaction.

RESULTS

We demonstrated that the deletion CNV variant was associated with a protective effect against CP in the French, German and Japanese cohorts whilst a trend toward the same association was noted in the Indian cohort. Meta-analysis under a dominant model yielded a pooled odds ratio (OR) of 0.68 (95% confidence interval (CI) 0.52-0.89; p = 0.005) whereas an allele-based meta-analysis yielded a pooled OR of 0.84 (95% CI 0.77-0.92; p = 0.0001). This protective effect is explicable by reference to the recent finding that the still functional PRSS3P2/TRY7 pseudogene enhancers upregulate pancreatic PRSS2 expression.

CONCLUSIONS

The common PRSS3P2 and TRY7 deletion CNV was associated with a reduced risk for CP. This finding provides additional support for the emerging view that dysregulated PRSS2 expression represents a discrete mechanism underlying CP predisposition or protection.

Molecular dynamics study of tropical calcific pancreatitis (TCP) associated calcium-sensing receptor single nucleotide variation

Tropical Calcific Pancreatitis (TCP) is a chronic non-alcoholic pancreatitis characterised by extensive calcification. The disease usually appears at a younger age and is more common in tropical regions. This disease’s progression can lead to pancreatic diabetes, which can subsequently lead to pancreatic cancer. The CASR gene encodes a calcium-sensing receptor (CaSR), which is a GPCR protein of class C. It is expressed in the islets of Langerhans, the parathyroid gland, and other tissues. It primarily detects small gradients in circulating calcium concentrations and couples this information to intracellular signalling, which helps to regulate PTH (parathyroid hormone) secretion and mineral ion homeostasis. From co-leading insulin release, CaSR modulates ductal HCO₃₋ secretion, Ca²⁺ concentration, cell-cell communication, β-cell proliferation, and intracellular Ca²⁺ release. In pancreatic cancer, the CaSR limits cell proliferation. TCP-related four novel missense mutations P163R, I427S, D433H and V477A, found in CaSR extracellular domain (ECD) protein, which were reported in the mutTCPdb Database (https://lms.snu.edu.in/mutTCPDB/index.php). P163R mutation occurs in ligand-binding domain 1 (LBD-1) of the CaSR ECD. To investigate the influence of these variations on protein function and structural activity multiple in-silico prediction techniques such as SIFT, PolyPhen, CADD scores, and other methods have been utilized. A 500 ns molecular dynamic simulation was performed on the CaSR ECD crystal structure and the corresponding mutated models. Furthermore, Principal Component Analysis (PCA) and Essential Dynamics analysis were used to forecast collective motions, thermodynamic stabilities, and the critical subspace crucial to CaSR functions. The results of molecular dynamic simulations showed that the mutations P163R, I427S, D433H, and V477A caused conformational changes and decreased the stability of protein structures. This study also demonstrates the significance of TCP associated mutations. As a result of our findings, we hypothesised that the investigated mutations may have an effect on the protein’s structure and ability to interact with other molecules, which may be related to the protein’s functional impairment.

A rare case of tropical chronic pancreatitis with giant pseudocyst: Case report

Background/objective

Tropical chronic pancreatitis (TCP) is common in developing countries and is defined as a juvenile form of chronic calcific non-alcoholic pancreatitis. Pseudocysts occur in 20-40% of chronic pancreatitis. TCP with pseudocyst has not been reported yet, so we represent this rare case to broaden the horizons regarding pancreatitis.

Case presentation

A 16-year-old woman suffered a painful lump in the upper abdomen. She came from a low-income family and frequently consumed cassava. There was intolerance of glucose in which admission blood sugar level of the patient increased by 179 mg/dl. An abdominal CT scan showed a mass around the pancreas, 20 cm in diameter, and located in retro-gastric. There were multiple ductal calculi along the major pancreatic duct with the largest stone was 3 cm in the pancreatic head. Longitudinal pancreaticojejunostomy (Partington-Rochelle procedure) has been performed and histopathological results appropriate with a pancreatic pseudocyst.

Clinical discussion

TCP with a giant pseudocyst is an interesting case report that has not been reported yet. This case met the clinical characteristics of TCP, such as young women, malnourished, history of cassava consumption, abdominal pain, and intolerance of glucose. A surgical intervention provides a satisfactory result to the patient.

Conclusion

Tropical chronic pancreatitis is a rare case. A pseudocyst adds the uniqueness of this case that has never been reported before. Appropriate management can provide satisfactory results and improve the quality of life for patients.

Natural history of SPINK1 germline mutation related-pancreatitis

BACKGROUND

The aim was to describe genetic, clinical and morphological features in a large, multicentre European cohort of patients with SPINK1 related pancreatitis, in comparison with patients with idiopathic pancreatitis (IP).

METHODS

All SPINK1 mutation carriers with pancreatic symptoms from two French and one English centers were included. Patients with IP were included in a control group. Genetic, clinical, radiological and biochemical data were collected.

FINDINGS

209 and 302 patients were included in the SPINK1 and control groups (median follow-up: 8.3 years (3.7-17.4) vs 5.3 (2.5-8.8)). The median age at onset of symptoms was 20.1 years (17.5-22.8) in the SPINK1 group versus 41.2 (35.2-45.2). The age of exocrine pancreatic insufficiency (EPI) onset in the SPINK1 group was 49.5 (44.5-54.6) years vs. 65.2 (62.1-68.3), p < 0.001. SPINK1 patients with EPI were 5.3%, 14.7%, 28.3% and 52.4% at 20, 30, 40 and 50 years. Diabetes occurred 37.7 (33.3-42.1) years following the onset of symptoms in the SPINK1 group vs. 30.6 (17.3-43.8) (p = 0.002). SPINK1 patients with diabetes were 7.8%, 13.4%, 26.3% and 43.4% at 30, 40, 50 and 60 years. Seven patients (3.3%) developed pancreatic cancer in the SPINK1 group (versus 3 (0.99%), p = 0.1), at a median age of 60 vs 66 years. The cancer risk was 0.8% before 50 years, 11.9%, 27.7%, 51.8% at 60, 70 and 80 years and was 12 times higher than in controls (Cox HR 12.0 (3.0-47.8), p < 0.001).

INTERPRETATION

SPINK1 related pancreatitis is associated with earlier onset and pancreatic insufficiencies. p.N34S SPINK1 may well be associated with cancer.

Structural, functional and molecular dynamics analysis of cathepsin B gene SNPs associated with tropical calcific pancreatitis, a rare disease of tropics

Tropical Calcific Pancreatitis (TCP) is a neglected juvenile form of chronic non-alcoholic pancreatitis. Cathepsin B (CTSB), a lysosomal protease involved in the cellular degradation process, has recently been studied as a potential candidate gene in the pathogenesis of TCP. According to the Cathepsin B hypothesis, mutated CTSB can lead to premature intracellular activation of trypsinogen, a key regulatory mechanism in pancreatitis. So far, CTSB mutations have been studied in pancreatitis and neurodegenerative disorders, but little is known about the structural and functional effect of variants in CTSB. In this study, we investigated the effect of single nucleotide variants (SNVs) specifically associated with TCP, using molecular dynamics and simulation algorithms. There were two non-synonymous variants (L26V and S53G) of CTSB, located in the propeptide region. We tried to predict the effect of these variants on structure and function using multiple algorithms: SIFT, Polyphen2, PANTHER, SDM sever, i-Mutant2.0 suite, mCSM algorithm, and Vadar. Further, using databases like miRdbSNP, PolymiRTS, and miRNASNP, two SNPs in the 3′UTR region were predicted to affect the miRNA binding sites. Structural mutated models of nsSNP mutants (L26V and S53G) were prepared by MODELLER v9.15 and evaluated using TM-Align, Verify 3D, ProSA and Ramachandran plot. The 3D mutated structures were simulated using GROMACS 5.0 to predict the impact of these SNPs on protein stability. The results from in silico analysis and molecular dynamics simulations suggested that these variants in the propeptide region of Cathepsin B could lead to structural and functional changes in the protein and thus could be pathogenic. Hence, the structural and functional analysis results have given interim conclusions that these variants can have a deleterious effect in TCP pathogenesis, either uniquely or in combination with other mutations. Thus, it could be extrapolated that Cathepsin B gene can be screened in samples from all TCP patients in future, to decipher the distribution of variants in patients.

mutTCPdb: a comprehensive database for genomic variants of a tropical country neglected disease-tropical calcific pancreatitis

Tropical calcific pancreatitis (TCP) is a juvenile, non-alcoholic form of chronic pancreatitis with its exclusive presence in tropical regions associated with the low economic status. TCP initiates in the childhood itself and then proliferates silently. mutTCPdb is a manually curated and comprehensive disease specific single nucleotide variant (SNV) database. Extensive search strategies were employed to create a repository while SNV information was collected from published articles. Several existing databases such as the dbSNP, Uniprot, miRTarBase2.0, HGNC, PFAM, KEGG, PROSITE, MINT, BIOGRID 3.4 and Ensemble Genome Browser 87 were queried to collect information specific to the gene. mutTCPdb is running on the XAMPP web server with MYSQL database in the backend for data storage and management. Currently, the mutTCPdb enlists 100 variants of all 11 genes identified in TCP, out of which 45 are non-synonymous (missense, nonsense, deletions and insertions), 46 are present in non-coding regions (UTRs, promoter region and introns) and 9 are synonymous variants. The database is highly curated for disease-specific gene variants and provides complete information on function, transcript information, pathways, interactions, miRNAs and PubMed references along with remarks. It is an informative portal for clinicians and researchers for a better understanding of the disease, as it may help in identifying novel targets and diagnostic markers, hence, can be a source to improve the strategies for TCP management.

Database URL: http://lms.snu.edu.in/mutTCPDB/index.php

Laparoscopic lateral pancreaticojejunostomy: an evolution to endostapled technique

BACKGROUND

Chronic pancreatitis (CP) is a debilitating condition resulting in severe pain with progressive deterioration of pancreatic function. "Tropical" pancreatitis represents a variant of the disease with widely dilated ducts, numerous calculi, and few strictures. Traditionally, modified Puestow's procedure has been the treatment of choice for a dilated pancreatic ductal system. However, it has only recently been adapted to laparoscopic approach which is a technically demanding procedure primarily due to need for extensive intra-corporeal suturing.

METHODS

Symptomatic cases of CP presenting at our center with minimum 8 mm mean ductal diameter at body and head were selected for laparoscopic modified Puestow's procedure. Those with prior pancreatic surgery, pancreatic head masses, endoscopic pancreatic stenting, and portal hypertension were excluded. Twenty-eight cases meeting selection criteria underwent a laparoscopic procedure.

RESULTS

Seven patients (25%) underwent a stapled pancreaticojejunal anastomosis, 17 (60.7%) received a sutured anastomosis. Four patients (14.3%) were converted to open surgery due to failure to localize the pancreatic duct with percutaneous needle aspiration. Of those patients who underwent a successful laparoscopic procedure, a single patient developed a pancreatic fistula which resolved spontaneously; another patient had a difficult post-operative course with prolonged intensive care. We suffered no mortality within the series and no patient had any long-term disability. Anastomotic patency rates of 100% were achieved by the third post-operative month.

CONCLUSION

Lateral pancreaticojejunostomy is an effective surgical management for CP with a dilated ductal system. Its laparoscopic adoption is the rational next surgical step. It allows effective duct decompression with low mortality and morbidity. The procedure demands an advanced surgical skill set with an emphasis on intra-corporeal suturing. Those patients suffering from tropical CP with wide ductal dilatation greater than 12 mm are suited to an endostapled anastomosis which helps significantly reduce operative time without any corrosion of outcomes.

A Case of Chronic Calcific Nonalcoholic Pancreatitis

Tropical Calcific Pancreatitis (TCP) is a type of chronic calcific nonalcoholic pancreatitis. Similar to nonalcoholic chronic pancreatitis, it presents in the second and third decades of life; however this type is reported mostly in the developing tropical and subtropical countries. It is associated with the formation of pancreatic calculi and a high probability of developing insulin-dependent diabetes mellitus. Epidemiologic studies have shown that these patients have an increased risk of developing pancreatic carcinoma. The etiology of TCP remains uncertain, with the current consensus suggesting genetics as well as possible toxicity from consuming large amounts of cassava, a tuber. Definite diagnosis of TCP requires younger age of onset, history of malnutrition, and presence of diabetes mellitus along with extensive pancreatic calcification and ductal calculi. When patients meet most but not all of these conditions the term Idiopathic Chronic Pancreatitis (ICP) is used. This is a case of a 44-year-old man who presented with most features seen in TCP, and however, was diagnosed with ICP.